Cyclopropanecarboxylic acids are important intermediate products for the production of pesticides and pharmaceuticals. Their esters can be used as miticides (German AS No. 2417372, the entire disclosure of which is hereby incorporated by reference and relied upon). 1-Methylcyclopropylcarboxanilido derivatives can be used as selective herbicides in the cultivation of soybeans (Pilgram U.S. Pat. No. 4,168,153 the entire disclosure of which is hereby incorporated by reference and relied upon).
4-Amino-6-(1-methylcyclopropyl)-3-methylthio-1,2,4-trizin-5-one represents a highly effective herbicide (Belgian Pat. No. 869138). For its synthesis there is needed 1-methylcyclopropanecarboxylic acid.
Other cyclopropanecarboxylic acids, e.g. 2-(2,2-dihalovinyl)-3,3-dialkyl cyclopropanecarboxylic acid and its ester are important key materials for the synthesis of a group of compounds which are known under the designation "synthetic pyrethroids" and which have noteworthy insecticide and acaricide activity.